Agilent U1271A/U1272A Handheld Digital Multimeter Service Guide Agilent Technologies
Notices © Agilent Technologies, Inc. 2010 Warranty No part of this manual may be reproduced in any form or by any means (including electronic storage and retrieval or translation into a foreign language) without prior agreement and written consent from Agilent Technologies, Inc. as governed by United States and international copyright laws. The material contained in this document is provided “as is,” and is subject to change, without notice, in future editions.
Safety Symbols The following symbols on the instrument and in the documentation indicate precautions which must be taken to maintain safe operation of the instrument.
Safety Considerations Read the information below before using this multimeter. The descriptions and instructions in this manual apply to the Agilent U1271A and U1272A Handheld Digital Multimeters (hereafter referred to as the multimeter). The model U1272A appears in all illustrations. CAUTION • Disconnect circuit power and discharge all high-voltage capacitors before testing resistance, continuity, diodes, or capacitance. • Use the proper terminals, function, and range for your measurements.
WA R N I N G • When measuring current, turn off the circuit power before connecting the multimeter in the circuit. Remember to place the multimeter in series with the circuit. • When servicing the multimeter, use only the specified replacement parts. • Use caution when working above 60 V DC, 30 V AC RMS, or 42.4 V peak. Such voltages pose a shock hazard. • Be aware of the presence of hazardous voltage before using the Low Pass Filter (LPF) function for voltage measurement.
Environmental Conditions This instrument is designed for indoor use and in an area with low condensation. The table below shows the general environmental requirements for this instrument.
Regulatory Markings The CE mark is a registered trademark of the European Community. This CE mark shows that the product complies with all the relevant European Legal Directives. The C-tick mark is a registered trademark of the Spectrum Management Agency of Australia. This signifies compliance with the Australia EMC Framework regulations under the terms of the Radio Communication Act of 1992. ICES/NMB-001 indicates that this ISM device complies with the Canadian ICES-001.
Waste Electrical and Electronic Equipment (WEEE) Directive 2002/96/EC This instrument complies with the WEEE Directive (2002/96/EC) marking requirement. This affixed product label indicates that you must not discard this electrical or electronic product in domestic household waste. Product Category: With reference to the equipment types in the WEEE directive Annex 1, this instrument is classified as a “Monitoring and Control Instrument” product. The affixed product label is as shown below.
Declaration of Conformity (DoC) The Declaration of Conformity (DoC) for this instrument is available on the Agilent Web site. You can search the DoC by its product model or description at the Web address below. http://regulations.corporate.agilent.com/DoC/search.htm NOTE U1271A/U1272A Service Guide If you are unable to search for the respective DoC, please contact your local Agilent representative.
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Table of Contents 1 Calibration Procedures Agilent Calibration Services 2 Closed case calibration 2 Calibration interval 2 Other recommendations for calibration Recommended Test Equipment Basic Operating Test 5 Backlight test 5 Display test 5 Current terminal input test 3 4 6 Calibration Process 8 Test considerations 8 Input connections 9 Performance Verification Tests Calibration Security 10 18 Unsecuring the Instrument for Calibration 19 To unsecure the instrument from the front panel 19 To change
2 Service and Maintenance Troubleshooting 34 Verifying the Fuse Health Fuse Replacement 35 38 Returning the Instrument for Service Replaceable Parts 43 To order replaceable parts 42 43 Types of Service Available 44 Extended service contracts 44 Obtaining Repair Service (Worldwide) XII 45 U1271A/U1272A Service Guide
List of Figures Figure 1-1 Figure 1-2 Figure 1-3 Figure 1-4 Figure 1-5 Figure 1-6 Figure 1-7 Figure 1-8 Figure 1-9 Figure 2-1 Figure 2-2 Figure 2-3 Figure 2-4 Figure 2-5 U1271A/U1272A Service Guide LCD display screen 5 A-Err display 6 μA-Err display 7 SECUr display 19 Calibration security code operation 20 SECUr display 21 SEr.
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List of Tables Table 1-1 Table 1-2 Table 1-3 Table 1-4 Table 2-1 Table 2-2 U1271A/U1272A Service Guide Recommended test equipment 4 Performance verification tests 10 Adjustment input values 24 Calibration error codes 31 Operating checklist 34 Fuse displayed readings 35 XV
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U1271A/U1272A Handheld Digital Multimeter Service Guide 1 Calibration Procedures Agilent Calibration Services 2 Closed case calibration 2 Calibration interval 2 Other recommendations for calibration 3 Recommended Test Equipment 4 Basic Operating Test 5 Backlight test 5 Display test 5 Current terminal input test 6 Calibration Process 8 Test considerations 8 Input connections 9 Performance Verification Tests 10 Calibration Security 18 Unsecuring the Instrument for Calibration 19 To unsecure the instrument fr
1 Calibration Procedures Agilent Calibration Services Agilent Calibration Services Agilent Technologies offers calibration services at competitive prices. When your instrument is due for calibration, contact your local Agilent Service Center for recalibration. See “Types of Service Available” on page 44 for more information on the various calibration services offered. Closed case calibration The U1271A and U1272A handheld digital multimeter features closed- case electronic calibration.
Calibration Procedures Agilent Calibration Services 1 Other recommendations for calibration Specifications are only guaranteed within the specified period from the last calibration. Agilent recommends that readjustment should always be performed at whatever calibration interval you select. This will ensure that the instrument remains within its specifications until the next calibration. This calibration criterion provides the best long- term stability.
1 Calibration Procedures Recommended Test Equipment Recommended Test Equipment The test equipment recommended for the performance verification and adjustment procedures is listed below in Table 1- 1. If the exact instrument is not available, substitute with another calibration standard of equivalent accuracy.
Calibration Procedures Basic Operating Test 1 Basic Operating Test The tests listed below are used to test the basic operability of the instrument. Repair is required if the instrument fails the any of the tests. • “Backlight test” • “Display test” • “Current terminal input test” Backlight test Press and hold the button while turning the rotary switch to any other position (OFF to ON). Check that the multimeter’s backlight is turned on. Press any key to exit this mode.
1 Calibration Procedures Basic Operating Test Current terminal input test This test determines if the input warnings of the current terminals are functioning properly. A-Err test The multimeter sounds a continuous alert beep when the test lead is inserted into the terminal but the rotary switch is not set to the function. The secondary display will indicate , as shown in Figure 1- 2.
Calibration Procedures Basic Operating Test 1 Figure 1-3 μA-Err display The alert beep tone will continue to beep until the test lead is removed from the terminal or until the rotary switch is set to the function. NOTE U1271A/U1272A Service Guide Before conducting this test, ensure that the beep function is not disabled in the multimeter’s Setup.
1 Calibration Procedures Calibration Process Calibration Process 1 Prior to performing the verification tests, see the “Test considerations” on page 8. 2 Perform the verification tests to characterize the multimeter; see “Performance Verification Tests” on page 10. 3 Unsecure the multimeter for calibration; see “Calibration Security” on page 18. 4 Prior to performing the adjustments, see the “Adjustment considerations” on page 23. 5 Perform the adjustment procedure; see “Adjustment procedure” on page 27.
Calibration Procedures Calibration Process 1 • Use shielded twisted pair Teflon- insulated cables to reduce settling and noise errors. Keep the input cables as short as possible. Long test leads can also act as antennas which may pick up AC signals. • Connect the input cable shields to earth ground. Please ensure that the calibration standards and test procedures used do not introduce additional errors.
1 Calibration Procedures Performance Verification Tests Performance Verification Tests Use the performance verification tests to verify the measurement performance of the instrument. The performance verification tests use the instrument's specifications listed in the U1271A/U1272A User's Guide (available for download at www.agilent.com/find/hhTechLib). The performance verification tests are recommended as acceptance tests when you first receive the instrument.
Calibration Procedures Performance Verification Tests 1 Table 1-2 Functional Test Error from nominal 1 year Step Test function 1 ACV Turn the rotary switch to the Range 3V position. 30 V 300 V 1000 V U1271A/U1272A Service Guide 5520 output U1271A U1272A 3 V, 20 Hz N/A ±0.0325 V 3 V, 45 Hz ±0.0230 V ±0.0200 V 3 V, 65 Hz ±0.0230 V ±0.0200 V 3 V, 1 kHz ±0.0325 V ±0.0325 V 3 V, 5 kHz ±0.0625 V ±0.0475 V 3 V, 20 kHz ±0.0640 V ±0.0640 V 2.7 V, 100 kHz N/A ±0.
1 Calibration Procedures Performance Verification Tests Table 1-2 Functional Test Error from nominal 1 year Step Test function LPF While the rotary switch is in the Shift Esc View 2 Range 3V position, press the key once. Frequency 5520 output U1271A U1272A 3 V, 20 Hz N/A ±0.0325 V 3 V, 45 Hz ±0.0230 V ±0.0200 V 3 V, 65 Hz ±0.0230 V ±0.0200 V 2.7 V, 430 Hz ±0.1375 V ±0.1375 V While the rotary switch is in the position, press the key once. 9.999 kHz 1.0000 kHz, 0.096 V ±0.005 kHz ±0.
Calibration Procedures Performance Verification Tests 1 Table 1-2 Functional Test Error from nominal 1 year Step Test function 5 DCV Turn the rotary switch to the 6 Range / position. AC+DCV switch to the press the Turn the rotary position, and key twice. U1271A U1272A 3V 3V ±0.0020 V ±0.0020 V 30 V 30 V ±0.017 V ±0.017 V 300 V 300 V ±0.17 V ±0.17 V 1000 V 1000 V ±0.7 V ±0.7 V 3V 3 V, 20 Hz N/A ±0.0360 V 3 V, 45 Hz N/A ±0.0235 V 3 V, 65 Hz N/A ±0.
1 Calibration Procedures Performance Verification Tests Table 1-2 Functional Test Error from nominal 1 year Step Test function Range 1000 V 7 DCmV[1] switch to the Turn the rotary / position. 30 mV 300 mV 5520 output U1271A U1272A 1000 V, 45 Hz N/A ±9.5 V 1000 V, 65 Hz N/A ±9.5 V 1000 V, 1 kHz N/A ±14.0 V 1000 V, 5 kHz N/A ±19.0 V 30 mV N/A ±0.035 mV –30 mV N/A ±0.035 mV 300 mV ±0.20 mV ±0.20 mV –300 mV ±0.10 mV ±0.
Calibration Procedures Performance Verification Tests 1 Table 1-2 Functional Test Error from nominal 1 year Step Test function 9 Resistance switch to the Range Turn the rotary / position. Smart 5520 output U1271A U1272A 30 Ω N/A ±0.070 Ω 300 Ω 300 Ω ±0.65 Ω ±0.65 Ω 3 kΩ[2] 3 kΩ ±0.0065 kΩ ±0.0065 kΩ 30 kΩ 30 kΩ ±0.065 kΩ ±0.065 kΩ 300 kΩ 300 kΩ ±1.55 kΩ ±0.65 kΩ 3 MΩ 30 Ω [2] [2] 3 MΩ ±0.0185 MΩ ±0.0185 MΩ [3] 30 MΩ ±0.365 MΩ ±0.365 MΩ 100 MΩ[3] 100 MΩ ±2.
1 Calibration Procedures Performance Verification Tests Table 1-2 Functional Test Error from nominal 1 year Step Test function 12 Range Temperature[4] While the rotary switch is in the position, press the key once. –200 °C to 1372 °C 5520 output U1271A U1272A –200 °C ± 3.0 °C ± 3.0 °C 0 °C ±1.0 °C ±1.0 °C 1372 °C ±14.7 °C ±14.7 °C Shift Esc View [4] Ensure that the ambient temperature is stable within ±1 ºC.
Calibration Procedures Performance Verification Tests 1 Table 1-2 Functional Test Error from nominal 1 year Step Test function 16 ACmA While the rotary switch is in the position, press the key once. Range U1271A U1272A 30 mA, 20 Hz N/A ±0.295 mA 30 mA, 45 Hz ±0.295 mA ±0.205 mA 30 mA, 65 Hz ±0.295 mA ±0.205 mA 30 mA, 1 kHz ±0.295 mA ±0.295 mA 300 mA, 20 Hz N/A ±2.95 mA 300 mA, 45 Hz ±2.95 mA ±2.05 mA 300 mA, 65 Hz ±2.95 mA ±2.05 mA 300 mA, 1 kHz ±2.95 mA ±2.95 mA 3A 3A ±0.
1 Calibration Procedures Calibration Security Calibration Security The calibration security code prevents accidental or unauthorized adjustments to the instrument. When you first receive your instrument, it is secured. Before you can adjust the instrument, you must unsecure it by entering the correct security code (see “Unsecuring the Instrument for Calibration” on page 19). NOTE The security code can only be changed after the instrument has been unsecured.
Calibration Procedures Unsecuring the Instrument for Calibration 1 Unsecuring the Instrument for Calibration Before you can adjust the instrument, you must unsecure it by entering the correct security code. The default security code is set to 1234. NOTE If you forget your security code, see “To reset the calibration security code to its factory default” on page 21.
1 Calibration Procedures Unsecuring the Instrument for Calibration If the incorrect security code is entered, an error code will appear at the secondary display briefly, after which the calibration security code entry mode will appear again.
Calibration Procedures Unsecuring the Instrument for Calibration 1 Figure 1-6 SECUr display 3 Set your new calibration security code. MaxMin Peak Press to the left. Press 4 Press Dual Exit or Hz % ms Log or Setup Range Auto to move the cursor to the right or to increment or decrement the digit. to save the new calibration security code. 5 If the new calibration security code has been successfully stored, the secondary display will show .
1 Calibration Procedures Unsecuring the Instrument for Calibration 1 Before you begin, note down the last four digits of the multimeter's serial number (located at the bottom of the multimeter’s rear panel). Shift Esc View Trig Auto Hold 2 Power- on the multimeter and press the and keys simultaneously for more that 1 second to enter the calibration security code entry mode. 3 is shown in the secondary display while the security code is shown in the primary display.
Calibration Procedures Using the Front Panel for Adjustments 1 Using the Front Panel for Adjustments This section describes the procedures to perform adjustments from the front panel. To unsecure the instrument, see “To unsecure the instrument from the front panel” on page 19. Once unsecured, the reference value will be indicated on the primary display. Figure 1-8 rEF display Adjustment considerations NOTE After each adjustment, the secondary display shows .
1 Calibration Procedures Using the Front Panel for Adjustments recommended to wait for 1 minute before you begin the calibration after connecting the test leads. 4 Before proceeding with the ambient temperature adjustment, be sure to turn on the multimeter for at least 1 hour with the K- type thermocouple connected. CAUTION Never turn off the multimeter during an adjustment. This may delete the calibration memory for the present function.
Calibration Procedures Using the Front Panel for Adjustments 1 Table 1-3 Adjustment input values (continued) Test function Step Reference value Valid reference input 3V 0.3000 V (70 Hz) 0.9 to 1.1 × Reference value 3.0000 V (70 Hz) 0.9 to 1.1 × Reference value 3.0000 V(3 kHz) 0.9 to 1.1 × Reference value 3.000 V (70 Hz) 0.9 to 1.1 × Reference value 30.000 V (70 Hz) 0.9 to 1.1 × Reference value 30.000 V(3 kHz) 0.9 to 1.1 × Reference value 30.00 V (70 Hz) 0.9 to 1.1 × Reference value 300.
1 Calibration Procedures Using the Front Panel for Adjustments Table 1-3 Adjustment input values (continued) Test function Step Reference value Valid reference input 30 mA 03.000 mA (70 Hz) 0.9 to 1.1 × Reference value 30.000 mA (70 Hz) 0.9 to 1.1 × Reference value 030.00 mA (70 Hz) 0.9 to 1.1 × Reference value 300.00 mA (70 Hz) 0.9 to 1.1 × Reference value 0.3000 A (70 Hz) 0.9 to 1.1 × Reference value 3.0000 A (70 Hz) 0.9 to 1.1 × Reference value 3.0000 A (70 Hz) 0.9 to 1.
Calibration Procedures Using the Front Panel for Adjustments 1 Table 1-3 Adjustment input values (continued) Test function Resistance Temperature Step Reference value Valid reference input SHORT SHORT SHORT Ω/COM terminals 30 MΩ OPEN OPEN terminals 10.000 MΩ 0.9 to 1.1 × Reference value 3 MΩ 3.0000 MΩ 0.9 to 1.1 × Reference value 300 kΩ 300.00 kΩ 0.9 to 1.1 × Reference value 30 kΩ 30.000 kΩ 0.9 to 1.1 × Reference value 3 kΩ 3.0000 kΩ 0.9 to 1.1 × Reference value 300 Ω 300.
1 Calibration Procedures Using the Front Panel for Adjustments NOTE While in the adjustment mode, press exit the adjustment mode. Shift Esc View and Trig Auto Hold simultaneously to 3 The primary display will show the reference value of the calibration item. Figure 1-9 rEF display 4 Configure each calibration item. MaxMin Peak 5 Use the , calibration range. Range Auto , Dual Exit , and Setup keys to select the 6 Apply the input signal shown in the Reference Value column of Table 1- 3.
Calibration Procedures Using the Front Panel for Adjustments 1 error number appears in the secondary display. The primary display remains at the current calibration item. NOTE If the adjustment fails, check the input value, range, function, and entered adjustment value before repeating the adjustment steps. 10 Turn the rotary switch to the next function according to the Test Function column shown in Table 1- 3. Repeat step 3 to step 8 for each adjustment point shown in the adjustment table.
1 Calibration Procedures Calibration Count Calibration Count You can query the instrument to determine how many adjustments have been performed. NOTE The multimeter was calibrated before it left the factory. You are recommended to record the initial value of the calibration count once you receive the multimeter. The count value increases by one for each calibration point, from 0000 up to the maximum of 19999. After the maximum count, the calibration count will reset to 0.
Calibration Procedures Calibration Error Codes 1 Calibration Error Codes The following errors indicate failures that may occur during a calibration.
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U1271A/U1272A Handheld Digital Multimeter Service Guide 2 Service and Maintenance Troubleshooting 34 Verifying the Fuse Health 35 Fuse Replacement 38 Returning the Instrument for Service 42 Replaceable Parts 43 To order replaceable parts 43 Types of Service Available 44 Obtaining Repair Service (Worldwide) 45 Extended service contracts 44 This chapter will help you troubleshoot a failing instrument. It also describes how to obtain repair services and lists the replaceable assemblies.
2 Service and Maintenance Troubleshooting Troubleshooting WA R N I N G To avoid electrical shock, do not perform any service unless you are qualified to do so. If the instrument fails to operate, check the batteries and the test leads. Replace them if necessary. And if the instrument still does not function, check the operating procedures in this manual. When servicing, use only the specified replacement parts. The table below will assist you in identifying some basic malfunctions.
Service and Maintenance Verifying the Fuse Health 2 Verifying the Fuse Health It is recommended that you check the fuse(s) of the multimeter before using it. Follow the instructions below to test the fuses inside the multimeter. NOTE Refer to Figure 2-5 for the respective positions of Fuse 1 (10 × 35 mm, 440 mA/1000 V fast-acting fuse) and Fuse 2 (10 × 38 mm, 11 A/1000 V fast-acting fuse). 1 Turn the rotary switch to the Smart / position and connect the red test lead to the input terminal.
2 Service and Maintenance Verifying the Fuse Health Smart Figure 2-1 Testing Fuse 1 36 U1271A/U1272A Service Guide
Service and Maintenance Verifying the Fuse Health 2 Smart Figure 2-2 Testing Fuse 2 U1271A/U1272A Service Guide 37
2 Service and Maintenance Fuse Replacement Fuse Replacement NOTE No recalibration is required after replacing the fuse. The current input terminals of your multimeter are fuse protected. The fuses are located next to the battery compartment. • The terminal is protected by a 10 × 35 mm 440 mA/1000 V 30 kA fast- acting fuse (Fuse 1). • The terminal is protected by a 10 × 38 mm 11 A/1000 V 30 kA fast- acting fuse (Fuse 2).
Service and Maintenance Fuse Replacement 2 1 2 3 Figure 2-3 Replacing Fuse 1 U1271A/U1272A Service Guide 39
2 Service and Maintenance Fuse Replacement 1 2 3 Figure 2-4 Replacing Fuse 2 40 U1271A/U1272A Service Guide
Service and Maintenance Fuse Replacement 2 Fuse 1: 10 × 35 mm 440 mA/1000 V fast-acting fuse Fuse 2: 10 × 38 mm 11 A/1000 V fast-acting fuse Figure 2-5 Positions of Fuse 1 and Fuse 2 U1271A/U1272A Service Guide 41
2 Service and Maintenance Returning the Instrument for Service Returning the Instrument for Service Before shipping your instrument for repair or replacement, Agilent recommends that you acquire the shipping instructions from the Agilent Technologies Service Center. A clear understanding of the shipping instructions is necessary to secure your product for shipment.
Service and Maintenance Replaceable Parts 2 Replaceable Parts This section contains information for ordering replacement parts for your instrument. You can find the instrument support part list at Agilent's Test & Measurement Parts Catalog: http://www.parts.agilent.com/ The parts lists include a brief description of each part with applicable Agilent part number. To order replaceable parts You can order replaceable parts from Agilent using the Agilent part number.
2 Service and Maintenance Types of Service Available Types of Service Available If your instrument fails during the warranty period, Agilent Technologies will repair or replace it under the terms of your warranty. After your warranty expires, Agilent offers repair services at competitive prices. Extended service contracts Many Agilent products are available with optional service contracts that extend the covered period after the standard warranty expires.
Service and Maintenance Obtaining Repair Service (Worldwide) 2 Obtaining Repair Service (Worldwide) To obtain service for your instrument (in- warranty, under service contract, or post- warranty), contact your nearest Agilent Technologies Service Center. They will arrange to have your unit repaired or replaced, and can provide warranty or repair- cost information where applicable.
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